This invention relates to a door construction and more particularly to a fabricated door construction which is exposed to high temperatures.
The invention is particularly applicable to use as a coke oven door or door assembly and will be described with particular reference thereto; however, it will be appreciated by those skilled in the art that the invention has broader applications and may be used in other environments where a door assembly which is exposed to high temperatures must resist or adapt to heat induced warpage which would otherwise prevent it from performing its intended function in the intended manner.
Coke oven is a term employed for large ovens which are used to produce coke and coke by-products from coal. While there are a number of types and styles of coke ovens, they typically have a substantial vertical height and depth in relation to the width and, in some respects, resemble a very large closet. In many instances, the height of these ovens is well over 10 feet and a substantial portion of the front faces thereof may be selectively opened and closed by means of a coke oven door. Normally, a plurality of the individual ovens are located in a side by side relationship to form what is commonly termed an oven battery in order that a high volume of coke and coke by-products may be simultaneously made at one location.
In the type of coke oven described above, an oven door frame is provided which, in actuality, normally covers or defines substantially the entire front wall of the oven itself. This frame has an opening which is elongated in the vertical direction and defines the coke oven access opening. Interposed between the outer peripheral surface of this elongated opening and the outer peripheral edges of the frame itself in a manner to extend outwardly from the outer face thereof is a support structure. This structure provides some rigid support for the frame in an effort to eliminate or at least reduce somewhat frame warpage encountered during a coking operation. Warpage is a significant problem due to the high temperatures, e.g., 2000.degree. F. and above acting on the inside face of the frame and door during such operations. Finally, a large elongated coke oven door is employed to selectively cover the coke oven access opening. The inside face of the oven door typically includes a sealing ring or diaphragm which seals the door against the door frame and which may be independently adjusted between defined limits relative to the door in order to maintain the desired sealing relationship at the occurrence of at least some heat induced warpage.
In prior coke ovens, the frames and oors have been constructed of cast iron and have typically been case by foundries to be very thick or heavy in order to withstand the elevated operating temperatures and to provide rigidity therefor. However, such cast iron frames have an extremely undesirable characteristic in that they will loose their original shape when subjected to elevated temperatures and "hour-glass" or otherwise warp. As they become distorted, it is extremely difficult to maintain a good sealing relationship between the coke oven door or sealing ring and the door frame. In that event, leaks develop around the oven door such that there are heat and pollution losses from the oven as well as air admission into the oven. Such circumstances are undesirable from both environmental and overall operational points of view.
While typical prior sealing ring arrangements have facilitated some independent adjustments thereof to reduce such leakage, they have proved ineffective when extreme frame "hour-glassing" or warping is present. Because prior coke oven doors were made of heavy cast iron for obtaining the most rigid door construction possible, the doors themselves would not conform to the warped configuration of the frame to aid in eliminating or at least reducing door leakage problems. Thus, once maximum adjustment for the prior sealing rings or diaphragms was obtained, there were no practical further steps which could be taken to insure proper door sealing.
The subject invention is directed toward a new and improved construction for a coke oven door which overcomes the above discussed problems and provides a new and improved door which is simple to manufacture, readily adaptable to use on the various types and styles of conventional coke ovens, provides a door structure which is strong and provides a door structure which is flexible in the event there is distortion incurred in the frame during coking operations.